期刊文献+
共找到691篇文章
< 1 2 35 >
每页显示 20 50 100
DESENSITIZATION OF ACETYLCHOLINE ON THE INHIBITION EFFECTS OF BLOOD PRE SSURE IN ANESTHETIZED CANINE 被引量:1
1
作者 陈莉娜 吕军 +3 位作者 臧伟进 于晓江 孙晓东 高小利 《Journal of Pharmaceutical Analysis》 SCIE CAS 2004年第2期167-170,共4页
Objective To investigate the desensitization of acetylcholine (ACh) on the inhibition effects of blood pressure (BP) in anesthe tized canine and build a model for studying desensitization in vivo. Methods Through ... Objective To investigate the desensitization of acetylcholine (ACh) on the inhibition effects of blood pressure (BP) in anesthe tized canine and build a model for studying desensitization in vivo. Methods Through changing the intervals (120, 100, 80, 60, 40, 20 seconds) of twice ACh administration (each was 15μg·kg -1,i.v.), the desensitization on the effect of systemic blood pressure of the first ACh in jection towards the subsequent ACh administration was observed. Results When ACh administration intervals were 40, 60, 80 , 100 seconds, the percentages of desensitization of ACh on systemic blood press ure were significantly increased (P<0.05). However, as the intervals were 20 and 120 seconds, the effects of twice ACh administration had no significant dif ference (P>0.05). Conclusion The results indicated that ACh contents in blo od might influence the action of next ACh administration. To some extent, the hi gher the concentration of ACh in blood, the bigger the ratio of desensitization of exogenous ACh is. In addition, this method of twice drug administration could be used as a model of studying desensitization in vivo. 展开更多
关键词 ACETYLCHOLINE DESENSITIZATION CANINE blood pre ssure
下载PDF
Tuning of band-gap of phononic crystals with initial confining pressure 被引量:2
2
作者 冯荣欣 刘凯欣 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期366-371,共6页
The mechanism of the shift of the band-gap in phononic crystal (PC) with different initial confining pressures is studied experimentally and numerically. The experimental results and numerical analysis simultaneousl... The mechanism of the shift of the band-gap in phononic crystal (PC) with different initial confining pressures is studied experimentally and numerically. The experimental results and numerical analysis simultaneously indicate that the confining pressure can efficiently tune the location in and the width of the band-gap. The present work provides a basis for tuning the band-gap of phononic crystal in engineering applications. 展开更多
关键词 phononic crystals band-gap initial confining pressure modified split-Hopkinson pres-sure bar apparatus
下载PDF
Research on inversion high mining pressure distribution and technology of preventing dynamic disasters by MS monitoring in longwall face 被引量:2
3
作者 CHENG Yun-hai JIANG Fu-xing ZOU Yin-hui 《Journal of Coal Science & Engineering(China)》 2009年第3期252-257,共6页
Under two rock strata combination conditions,over 10,000 microseismic eventswere received with microseismic location monitoring technology which possessed by theauthor's studying team,used in fully mechanized coal... Under two rock strata combination conditions,over 10,000 microseismic eventswere received with microseismic location monitoring technology which possessed by theauthor's studying team,used in fully mechanized coal face of Huafeng Mine of XinwenCoal Mining Group Co.,Shandong Province.On the basis of the achievement of the locationresults,the conclusions were drawn as follows:On the basis of the achievement of 3Dstrata fracturing situation and the section plane of microseimic events in different areas,the relationship between spatial structure of overlying strata and mining pressure field wasfound,and we might describe distribution range of dynamic pressure of advance pressureand lateral stress around long face,and range of structure ad-tivation.Quantitative guidanceto prevent dynamic disasters was provided.The practice in coal mine got a effectiveresults.According to the FLAC3D soft numerical simulation of diameter drilling hole (thediameter is 300 mm) to relieve pressure in specified geological condition in Huafeng Mine,the right distance of two dirlls is 2.5 m and the right depth is 12 m.The research pro-videdbasic guiding and practical experiences for the underground microseismic monitoring anddisaster prevention in side slopes or tunnels engineering. 展开更多
关键词 压力分布 开采技术 动态监测 灾害 反演 MS 华丰煤矿 上覆岩层
下载PDF
Contribution to the Improvement of Transfusion Safety: Assessment of the Pre-Donation Hemoglobin Level at the Yamoussoukro Blood Transfusion Center in Cote d’Ivoire
4
作者 Renaude Janine Amon Boukalo Guillaume Zaminan +5 位作者 Martial Bama Saydou Kaboré Sidonie Gooré Kouamenan Issaka Tiembré Jean-Jacques Dadié Bosso Sekongo Yassongui Mamadou 《Open Journal of Blood Diseases》 2023年第2期78-82,共5页
Introduction: Despite the progress recorded at the level of transfusion safety in Côte d’Ivoire, much remains to be done, particularly at the level of the medical selection of blood donors. The objective of the ... Introduction: Despite the progress recorded at the level of transfusion safety in Côte d’Ivoire, much remains to be done, particularly at the level of the medical selection of blood donors. The objective of the study was to make an assessment of the pre-donation capillary hemoglobin dosage for the year 2020 of the fixed collection, of the Blood Transfusion Center of Yamoussoukro. Method: This is a retrospective study that took place at the Yamoussoukro Blood Transfusion Center. The data collection related to all old and new blood donors were deemed suitable for the fixed collection of the year 2020. The method chosen for the pre-donation control is that of the portable hemoglobinometer of the HémoCue<sup>®</sup> type, more precisely 201+. Results: Of the 1160 blood donors in the study, the pre-donation hemoglobin level was not measured in 787 (67.8%) subjects of either sex. Of the subjects who had a pre-donation hemoglobin level performed, 97 (26%) blood donors had a sub-standard hemoglobin level, including 15 females and 82 males. Conclusion: Pre-donation hemoglobin testing of blood donors is effective in Yamoussoukro. However, efforts must still be made to improve the quality of the blood collected and to protect blood donors. 展开更多
关键词 blood Donation Medical Selection pre-Donation Hemoglobin Fixed Collection Yamoussoukro
下载PDF
Synthesis of Cu-Doped Mixed-Phase TiO_2 with the Assistance of Ionic Liquid by Atmospheric-Pressure Cold Plasma
5
作者 詹志彬 底兰波 +1 位作者 张秀玲 李燕春 《Plasma Science and Technology》 SCIE EI CAS CSCD 2016年第5期494-499,共6页
An atmospheric-pressure dielectric barrier discharge (DBD) gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid (IL) a... An atmospheric-pressure dielectric barrier discharge (DBD) gas-liquid cold plasma was employed to synthesize Cu-doped TiO~ nanoparticles in an aqueous solution with the assistance of [C2MIM]BF4 ionic liquid (IL) and using air as the working gas. The influences of the discharge voltage, IL and the amount of copper nitrite were investigated. X-ray diffraction, N2 adsorption-desorption measurements and UV-Vis spectroscopy were adopted to characterize the samples. The results showed that the specific surface area of TiO2 was promoted with Cu-doping (from 57.6 m^2.g^-1 to 106.2 m^2.g^-1 with 3% Cu-doping), and the content of anatase was increased. Besides, the band gap energy of TiO~ with Cu-doping decreased according to the UV-Vis spec- troscopy test. The 3%Cu-IL-TiO2 samples showed the highest eificiency in degrading methylene blue (MB) dye solutions under simulated sunlight with an apparent rate constant of 0.0223 min-1, which was 1.2 times higher than that of non-doped samples. According to the characterization results, the reasons for the high photocatalytic activity were discussed. 展开更多
关键词 dielectric barrier discharge (DBD) gas-liquid cold plasma atmospheric pres-sure mixed-phase Ti02 Cu-doped
下载PDF
The Mechanical Environment of the Cells in a Membrane Pressure-tension Compound Loading System:An Experimental and Theoretical Study
6
作者 ZOU Yuan-wen HE Gang +2 位作者 HUANG Xue-jin LI Jin-chuan JIANG Wen-tao 《Chinese Journal of Biomedical Engineering(English Edition)》 2013年第3期111-118,共8页
A quasi-static/dynamic pressure-tension compound loading system was established in this paper for the research of cellular mechanical circumstances. Both radical and circumferential strain of the basement membrane wer... A quasi-static/dynamic pressure-tension compound loading system was established in this paper for the research of cellular mechanical circumstances. Both radical and circumferential strain of the basement membrane were studied and compared in theoretical calculations by using the FEA Software ABAQUS and experimental measurements. The tension of the basement membrane was studied both in ABUQUES results and experimental results, the relation between the height of the concave cavity, the radius of the membrane and the strain of the membrane were studied in details. 展开更多
关键词 COMPOUND loading system cellular MECHANICS static/dynamic pressure CONCAVE cavity BASEMENT MEMBRANE
下载PDF
Factors Predicting Transformation of Non-Severe Pre-Eclampsia into Pre-Eclampsia with Severe Features
7
作者 Mohammed Mahmoud Samy Ahmed Nagy Abdul-Rahman Younis Karim Mohammed Labib 《Open Journal of Obstetrics and Gynecology》 CAS 2023年第2期153-165,共13页
Background: Pre-eclampsia (PE), a complex, multisystem, pregnancy-associated hypertensive disorder, typically developing after the 20<sup>th</sup> week of gestation, that complicates 2% - 8% of pregnancies... Background: Pre-eclampsia (PE), a complex, multisystem, pregnancy-associated hypertensive disorder, typically developing after the 20<sup>th</sup> week of gestation, that complicates 2% - 8% of pregnancies, is a leading cause of neonatal and maternal mortality and morbidity. Aim of the Work: To identify different factors predicting transformation of non-severe pre-eclampsia in to pre-eclampsia with severe features. Patients and Methods: This prospective cohort study was conducted at tertiary care hospital at Ain Shams University hospitals from June 2021 till January 2022 and performed on total of 100 patients who diagnosed as non-severe pre-eclampsia after exclusion of severity features. Results: The current study revealed that transformation to severe pre-eclampsia occurred in 33% of the studied cases. Body mass index (BMI), past and family histories of preeclampsia statistically were significantly higher in cases transformed into preeclampsia with severe features. Admission blood pressure, albumin dipstick, Oligohydramnios and IUGR statistically were significantly higher in cases with transformation from non-severe pre-eclampsia into pre-eclampsia with severe features. Platelet count statistically was significantly lower in cases with transformation from non-severe pre-eclampsia into pre-eclampsia with severe features Conclusion: Our study results identified the most important clinical risk factors for transformation to severe features of pre-eclampsia from non-severe features and provided new information on the level of risk associated with specific combinations of risk factors (BMI ≥ 35.4, admission systolic blood pressure, admission diastolic blood pressure, albumin dipstick 4+ and platelets count) with low significant diagnostic performance in predicting transformation from non-severe pre-eclampsia into pre-eclampsia with severe features. 展开更多
关键词 pre-ECLAMPSIA blood pressure Body Mass Index Platelet Count
下载PDF
Labetalol versus Hydralazine in the Management of Severe Pre-Eclampsia at Tertiary Hospitals in a Low-Resource Setting: A Randomised Controlled Trial
8
作者 Uzoma Otutoaja Adeyemo Olabisi Timothy +7 位作者 Emmanuel Olumide Adewara Olufunmilayo Victoria Adebara Augustine Adebayo Adeniyi Babatunde Sunday Awoyinka Raymond Akujuobi Okere Idowu Oluseyi Adebara Adewumi Bakare Mojisola Olumide Ayankunle 《Open Journal of Obstetrics and Gynecology》 2023年第6期1058-1067,共10页
Objective: Intravenous labetalol and hydralazine are both considered first-line medications for the management of acute-onset, severe hypertension in pregnant and postpartum women. The study compared the efficacy and ... Objective: Intravenous labetalol and hydralazine are both considered first-line medications for the management of acute-onset, severe hypertension in pregnant and postpartum women. The study compared the efficacy and safety profile of intravenous labetalol and hydralazine in the control hypertension in severe pre-eclampsia. Materials and Methods: One hundred patients who presented with severe pre-eclampsia were randomized into two study groups. The fifty patients in each arm of the study received either intravenous labetalol or intravenous hydralazine for the control of blood pressure. Results: The mean age of the labetalol subjects was 28.6 ± 5.47 years while that of their hydralazine counterparts was 29.12 ± 5.77 years. The majority of respondents in both groups were primigravidae (76% vs. 78%) (P = 0.813). The number of doses of drug needed to significantly lower the mean systolic blood pressure was slightly lower in the labetalol group (2 doses) compared to the hydralazine group (5 doses) (t = 0.803<sup>Y</sup>, P = 0.977). The incidence of headaches which were the commonest complaints was comparable in both groups 8% and 10% of respondents respectively (P > 0.05). Conclusion: Although both intravenous labetalol and hydralazine are useful in patients with severe pre-eclampsia, the response to labetalol was better with comparable side effects. 展开更多
关键词 blood pressure HYDRALAZINE LABETALOL Low-Resource Setting Severe pre-Eclampsia Side Effects
下载PDF
白细胞介素1受体颉颃剂抑制脂多糖促奶牛外周血单个核细胞氧化应激损伤作用的研究
9
作者 郭咏梅 齐敬宇 +2 位作者 闫素梅 赵艳丽 郭晓宇 《饲料工业》 CAS 北大核心 2024年第4期100-105,共6页
试验以脂多糖(LPS)为刺激源,以细胞活力、抗氧化指标和炎症因子为判断指标,探讨白细胞介素1受体颉颃剂(IL-1Ra)通过抑制白细胞介素1β(IL-1β)的活性,对LPS诱导外周血单个核细胞(Peripheral blood mononuclear cells,PBMCs)氧化损伤的... 试验以脂多糖(LPS)为刺激源,以细胞活力、抗氧化指标和炎症因子为判断指标,探讨白细胞介素1受体颉颃剂(IL-1Ra)通过抑制白细胞介素1β(IL-1β)的活性,对LPS诱导外周血单个核细胞(Peripheral blood mononuclear cells,PBMCs)氧化损伤的缓解作用。试验采用单因子完全随机设计,PBMCs被随机分为7个组(每组6个重复),分别给予不同的处理:第1组是阴性对照组(Neg组),完全培养基培养30 h;第2组损伤组(Dam组),是在完全培养基中培养6 h后,再经10μg/mL的LPS工作液培养24 h;第3至7组(R0.25、R0.5、R1、R5组和R10组)细胞分别经浓度为0.25、0.5、1、5、10 ng/mL的IL-1Ra培养6 h,接着经10μg/mL的LPS工作液培养24 h。结果表明:与Neg组相比,Dam组的细胞活力、抗氧化相关酶[包括总抗氧化能力(T-AOC)以及总超氧化物歧化酶(T-SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)和硫氧还蛋白还原酶(TrxR)]的活性显著降低,丙二醛(MDA)浓度、炎症因子白细胞介素-6(IL-6)和IL-1β含量以及诱导型一氧化氮合酶(iNOS)活性、一氧化氮(NO)含量均显著升高(P≤0.05)。与Dam组相比,R1组显著逆转了氧化损伤引起的上述抗氧化活性的降低和炎症因子浓度的升高,其他IL-1Ra处理组对上述指标的逆转效果不同程度地低于R1组(P≤0.05)。上述结果说明,LPS通过诱发PBMCs产生大量IL-1β进而导致细胞氧化损伤,IL-1Ra剂量依赖性地缓解了LPS引起的氧化损伤,添加剂量以1 ng/mL为宜。 展开更多
关键词 奶牛外周血单个核细胞 氧化应激 剂量依赖性 白细胞介素1受体颉颃剂 预保护作用
下载PDF
可穿戴人体无创血压测量技术
10
作者 高铁成 刘璨 +1 位作者 戈立军 马宇洁 《天津工业大学学报》 CAS 北大核心 2024年第2期83-88,共6页
针对传统的连续无创血压测量设备结构复杂、体积大、不宜穿戴、限制患者运动等问题,设计一种可穿戴设备对人体血压进行实时无创测量。通过硬件设备同步获取心电-脉搏波信号,设计信号处理算法,提取特征点用于后续血压估计。应用MIMIC数... 针对传统的连续无创血压测量设备结构复杂、体积大、不宜穿戴、限制患者运动等问题,设计一种可穿戴设备对人体血压进行实时无创测量。通过硬件设备同步获取心电-脉搏波信号,设计信号处理算法,提取特征点用于后续血压估计。应用MIMIC数据中心电-脉搏-血压信号计算脉搏波传导时间及射血前期,并利用最小二乘法进行线性回归分析,构建血压测量模型,实现个性化血压检测算法。实验验证结果表明:采用该技术检测人体血压时,误差的标准差在±8 mmHg(1 mmHg≈133 Pa)范围内,平均绝对误差小于5 mmHg,满足AAMI国际血压计准确性评价标准的要求。 展开更多
关键词 无创血压测量 脉搏波传导时间 可穿戴 射血前期
下载PDF
水声材料声学参数测试技术的进展
11
作者 曹锃 佟昊阳 +5 位作者 易燕 颜士玲 黄唯纯 李水 陈毅 赵涵 《中国材料进展》 CAS CSCD 北大核心 2024年第1期79-88,共10页
水声材料是水下声系统能力形成和发展的基础,其声学参数测试技术是确保水声材料构件功能实现的重要保障,然而目前水声材料构件的测试技术面临着低频拓展及高压拓展等方面带来的技术挑战。水声材料构件的声管测试技术可分为驻波管法、脉... 水声材料是水下声系统能力形成和发展的基础,其声学参数测试技术是确保水声材料构件功能实现的重要保障,然而目前水声材料构件的测试技术面临着低频拓展及高压拓展等方面带来的技术挑战。水声材料构件的声管测试技术可分为驻波管法、脉冲管法和行波管法,此3种方法在适用性方面相互补充,但存在测试构件尺寸小难以阐明结构的整体特性、构件与管壁间的缝隙造成测量失准的问题。自由场测试技术及压力罐测试技术是大面积水声材料测试的有效手段,但存在测试构件边缘衍射造成测量准确性降低的问题。对目前采用的水声材料测试技术及其研究现状进行了综述,讨论了各类测试技术存在的困难和挑战,并展望了水声材料构件测试技术未来的发展方向。 展开更多
关键词 水声材料 声管 自由场 压力罐 低频 高压 边缘衍射
下载PDF
膳食纤维摄入对原发性高血压患者血压控制的预测价值
12
作者 刘彬 朱红英 +2 位作者 李文霞 汪小华 张志蓉 《实用临床医药杂志》 CAS 2024年第3期126-130,共5页
目的 探讨膳食纤维摄入对高血压人群血压控制的预测作用。方法 采用前瞻性观察性研究设计,收集患者3 d饮食日记以获得膳食纤维摄入量;跟踪至3个月时,记录24 h动态血压,分析获得平均收缩压和平均舒张压。采用受试者工作特征(ROC)曲线评... 目的 探讨膳食纤维摄入对高血压人群血压控制的预测作用。方法 采用前瞻性观察性研究设计,收集患者3 d饮食日记以获得膳食纤维摄入量;跟踪至3个月时,记录24 h动态血压,分析获得平均收缩压和平均舒张压。采用受试者工作特征(ROC)曲线评价膳食纤维摄入对血压控制的预测作用。结果 获得166例患者的完整膳食营养摄入情况,其中获得148例患者的血压资料。回归分析显示,膳食纤维摄入对收缩压(OR=0.897,95%CI:0.839~0.960)有积极影响,且对收缩压有较好的预测作用[曲线下面积(AUC)=0.715,灵敏度为60.0%,特异度为76.9%]。膳食纤维摄入并未对舒张压产生积极的影响。结论 膳食纤维摄入对高血压人群的收缩压控制有较好的预测作用,但未能有效预测舒张压的控制情况。 展开更多
关键词 高血压 膳食纤维摄入 预测价值 24 h动态血压监测 血压控制
下载PDF
谷精草汤化裁方对肝郁化火证高血压病患者血压、肾素活性、血管紧张素Ⅱ及醛固酮的影响
13
作者 赵存方 王强 +6 位作者 李惠洲 史佳森 王春亮 毕俊芳 崔晓慧 万鑫苗 申雪娜 《临床误诊误治》 CAS 2024年第9期89-94,共6页
目的观察谷精草化裁方联合厄贝沙坦片治疗对肝郁化火证高血压病患者血压、肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)及醛固酮(ALD)水平的影响。方法选取2022年1月-2023年2月收治的80例肝郁化火证高血压病,按照随机数字表法分为2组,对照组40... 目的观察谷精草化裁方联合厄贝沙坦片治疗对肝郁化火证高血压病患者血压、肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)及醛固酮(ALD)水平的影响。方法选取2022年1月-2023年2月收治的80例肝郁化火证高血压病,按照随机数字表法分为2组,对照组40例予厄贝沙坦片治疗,观察组40例在对照组基础上加用谷精草化裁方治疗,2组均治疗8周。比较2组治疗前后血压相关指标、中医证候积分和血清PRA、AngⅡ和ALD水平变化,以及治疗期间不良反应情况。结果治疗8周后,观察组总有效率为92.50%(37/40)高于对照组的75.00(30/40)(P<0.05)。治疗后,2组日间收缩压、日间舒张压、夜间收缩压、夜间舒张压、24 h收缩压、24 h舒张压、血压负荷均较治疗前下降,且观察组优于对照组(P<0.05)。治疗后,观察组各项中医证候积分下降,而对照组仅眩晕、头痛积分降低(P<0.05);治疗后,观察组各项中医证候积分优于对照组(P<0.05)。2组治疗后血清PRA较治疗前升高,AngⅡ和ALD较治疗前降低(P<0.05);观察组治疗后PRA水平高于对照组,AngⅡ和ALD水平低于对照组(P<0.05)。2组不良反应发生率比较差异无统计学意义(P>0.05)。结论谷精草汤化裁方联合厄贝沙坦片治疗肝郁化火证高血压病,可降低患者血压,改善患者临床症状,并能有效抑制AngⅡ和ALD水平,效果显著且安全。 展开更多
关键词 高血压 肝郁化火 谷精草汤化裁方 血压 中医证候 肾素活性 血管紧张素Ⅱ 醛固酮
下载PDF
LISA技术治疗超低出生体质量儿呼吸窘迫综合征28例
14
作者 赵明明 刘玉娟 +1 位作者 李忠良 刘小娜 《安徽医药》 CAS 2024年第1期143-147,共5页
目的探讨经鼻持续气道正压通气(nasal continuous positive airway pressure,nCPAP)下经微管气管内注入肺表面活性物质(less invasive surfactant administration,LISA)技术在超低出生体质量儿呼吸窘迫综合征(respiratory distress synd... 目的探讨经鼻持续气道正压通气(nasal continuous positive airway pressure,nCPAP)下经微管气管内注入肺表面活性物质(less invasive surfactant administration,LISA)技术在超低出生体质量儿呼吸窘迫综合征(respiratory distress syndrome,RDS)治疗中的应用与疗效。方法采取前瞻性研究方法,选取潍坊市妇幼保健院新生儿科重症监护病房(neonatalintensive careunit,NICU)2019年7月至2021年4月收治的超低出生体质量儿(58例)为研究对象。应用随机数字表法分为LISA组(28例)和气管插管-注入PS-拔管给予经鼻持续气道正压通气(intubation-surfactant-extubation,INSURE)组(30例)。LISA组采用LISA技术,在nCPAP下,气管内置入微管并注入肺表面活性物质(pulmonarysurfactant,PS);INSURE组采用INSURE技术,拔管后给予nCPAP辅助通气。观察并比较两组病儿给药过程、给药前后呼吸机参数、动脉血气、用氧时间及并发症的发生率。结果LISA组病儿72 h内机械通气率低于INSURE组,差异有统计学意义(21.4%比46.7%,P=0.043);LISA组病儿住院期间无创正压通气时间(404.50 h比483.50 h,P=0.033)及总用氧时间(520.00 h比612.50 h,P=0.040)低于INSURE组;LISA组给药1 h后动脉血氧分压(arterial partialpressureof O_(2),PaO_(2))变化高于INSURE组[(54.29±5.69)mmHg比(52.87±3.27)mmHg,P=0.038],差异有统计学意义;LISA组支气管肺发育不良(25.0%比53.3%,P=0.028)及有血流动力学意义的动脉导管未闭发生率(28.6%比56.7%,P=0.031)低于INSURE组,均差异有统计学意义。结论在超低出生体质量儿RDS治疗中,LISA技术在减少72 h内机械通气率、住院期间用氧时间、近期并发症等方面具有优势,是一种安全有效的治疗超低出生体质量儿RDS的方法。 展开更多
关键词 呼吸窘迫综合征 新生儿 肺表面活性物质相关蛋白质类 连续气道正压通气 经微管气管内注入肺表面活性物质(LISA) 婴儿 超低出生体质量
下载PDF
降雨条件下土质挖方边坡的稳定性分析
15
作者 索增辉 徐晓琪 《矿产勘查》 2024年第7期1278-1285,共8页
边坡开挖会对原始斜坡体产生卸荷效应,降低了土坡抵抗外界荷载的能力,降雨入渗后易引发灾害,给边坡安全施工造成威胁。本文采用非饱和土抗剪强度理论,结合Morgenstern-Price条分法,对不同放坡角度下边坡的稳定性进行分析,同时采用具有... 边坡开挖会对原始斜坡体产生卸荷效应,降低了土坡抵抗外界荷载的能力,降雨入渗后易引发灾害,给边坡安全施工造成威胁。本文采用非饱和土抗剪强度理论,结合Morgenstern-Price条分法,对不同放坡角度下边坡的稳定性进行分析,同时采用具有不同降雨峰值的两组72 h实测降雨值,动态分析了边坡安全系数,同时探讨了孔隙水压力的变化规律。结果表明:(1)土体饱和度随基质吸力增加而不断减小;(2)由于粉细砂渗透系数大,同一吸力水平下,饱和度下降最快,其次为淤泥质壤土,而黏土的饱和度下降最慢,储水能力最好;(3)随着坡角增大,边坡的潜在滑动面会逐渐靠近开挖形成的临空面,即滑坡的体积会减小,边坡的安全系数越低;(4)总体上随着降雨时长增大,边坡的安全系数呈逐渐减小的趋势,但局部出现了回升的现象。因此在进行实际切坡工程时,应当尽量降低坡角来保持边坡稳定性,对于需要留取较陡边坡的工程,应采取相应的加固措施来防止边坡出现滑坡等灾害。同时,采用实际降雨数据对边坡稳定性分析能够真实反映边坡安全系数边坡变化,对边坡稳定性设计具有实际意义。 展开更多
关键词 挖方边坡 降雨入渗 边坡稳定性 Morgenstern-Price法 孔隙水压力
下载PDF
坚硬灰岩顶板破断对煤层底板破坏特征
16
作者 王永凯 陈军涛 范铭今 《山东煤炭科技》 2024年第1期32-36,共5页
为研究坚硬灰岩顶板破断对煤层底板变形破坏的影响,以黄河北煤田邱集煤矿111107工作面为背景,基于顶板岩体破断动载应力函数,运用FLAC^(3D)模拟了坚硬灰岩顶板破断对采空区底板的破坏过程,对比了不同动载幅值下采空区底板破坏特征,基于... 为研究坚硬灰岩顶板破断对煤层底板变形破坏的影响,以黄河北煤田邱集煤矿111107工作面为背景,基于顶板岩体破断动载应力函数,运用FLAC^(3D)模拟了坚硬灰岩顶板破断对采空区底板的破坏过程,对比了不同动载幅值下采空区底板破坏特征,基于深孔聚能爆破预裂技术,设计了爆破切顶方案,为坚硬灰岩顶板工作面安全开采提供保障。模拟结果表明:动载作用前后底板破坏范围和深度有明显增加,底板最大破坏深度达12 m,动载作用结束以后,残余应力波仍持续影响采场底板,直到灰岩顶板破断150 ms后,采场底板的动力响应才全部结束;随着动载幅值增大,底板破坏范围逐步增大;在持续时间相同的条件下,当幅值小于10 MPa时,动载作用前后底板破坏变化不明显;当幅值大于10 MPa时,动载作用前后底板破坏有明显变化。 展开更多
关键词 坚硬灰岩 顶板破断 深孔聚能爆破 切顶卸压
下载PDF
《黄帝内经》“血脉”整体观防治动脉粥样硬化性心血管疾病的理论发挥
17
作者 张铜五 陈向心 +8 位作者 陆毅 郝秀炜 王洋 关乐 刘悦 张哲 闵冬雨 杨关林 孔德昭 《实用中医内科杂志》 2024年第6期1-4,共4页
《黄帝内经》有云:“人之所以成生者,血脉也”“血脉和利,精神乃居”“血”,维系着机体的正常生理功能;“脉”,则具有推动和约束血液在脉道运行的作用;“血”与“脉”相互作用,二者相合,共同维持着机体的生命活动。传承《黄帝内经》的... 《黄帝内经》有云:“人之所以成生者,血脉也”“血脉和利,精神乃居”“血”,维系着机体的正常生理功能;“脉”,则具有推动和约束血液在脉道运行的作用;“血”与“脉”相互作用,二者相合,共同维持着机体的生命活动。传承《黄帝内经》的思想和理论,杨关林教授从中医学“整体观”出发,结合前人“痰瘀”相关学说,整体审视心脑血管系统疾病,提纲挈领地提出“血脉病”这一概念。血脉病,指气血运行失常,导致血脉痹阻的一类疾病,包含心脉病、脑脉病和肢脉病等多系统疾病。血脉病的发生与脾虚受损有密切的联系,我们创新性的将血脉病分为“血浊脉滞”“血瘀脉壅”“血毒脉损”三个不同发展阶段,并根据不同阶段的病机和临床表现提出“健脾益气,化痰降浊”“健脾益气,化痰祛瘀”“化痰祛瘀,清热解毒”三种不同的治法并建立出相应中药组方,构建血脉病全程防治体系,提升中医药防治疗效。 展开更多
关键词 黄帝内经 血脉病 中医药 脾虚受损 防治体系 动脉粥样硬化性心血管疾病
下载PDF
喷油特性对F-T煤制油压力振荡影响规律研究
18
作者 冀冠佐 王铁 +1 位作者 石晋宏 王浩亚 《机械设计与制造》 北大核心 2024年第4期189-193,共5页
为了减小燃烧噪声,确定影响柴油机高频压力振荡的关键因素,在某型电控高压共轨柴油发动机上燃用的清洁代用燃料Fischer-Tropsch(F-T)煤制油,选取柴油机典型运行工况,研究不同喷油特性条件下柴油机燃烧压力振荡的时域和频域特性。结果表... 为了减小燃烧噪声,确定影响柴油机高频压力振荡的关键因素,在某型电控高压共轨柴油发动机上燃用的清洁代用燃料Fischer-Tropsch(F-T)煤制油,选取柴油机典型运行工况,研究不同喷油特性条件下柴油机燃烧压力振荡的时域和频域特性。结果表明:推后主喷提前角和提前预喷提前角会使放热率降低,压力振荡幅值减小,气缸压力级也有明显减小的趋势;减小预喷油量会使压力升高率和放热率降低,气缸声压级减小,压力振荡现象减缓,使燃烧更加柔和;提高喷射压力,会使喷油速率增大,燃油雾化效果增强,混合气放热率提升,放热率曲线也随之上升,气缸声压级增大,发动机缸内燃烧压力振荡幅值增大。喷射压力是影响压力振荡的最显著的参数,喷射压力从85MPa上升至115MPa时,压力振荡幅值增加一倍以上;预喷油量对F-T煤制油发动机的燃烧压力振荡影响不显著;同时压力振荡的产生与放热率的变化呈现出较强的相关性。 展开更多
关键词 高压共轨柴油机 F-T煤制油 燃烧特性 压力振荡 喷油特性
下载PDF
血清miR-503、miR-520h对妊娠期糖尿病患者并发子痫前期的诊断价值
19
作者 杨娜 郭燕 +2 位作者 郭润丽 魏咏梅 安楠 《检验医学与临床》 CAS 2024年第13期1899-1904,共6页
目的探讨血清微小核糖核酸-503(miR-503)和微小核糖核酸-520h(miR-520h)对妊娠期糖尿病(GDM)患者并发子痫前期(PE)的诊断价值。方法选取2019年12月至2021年12月于唐山中心医院产科定期产检并建档的GDM患者102例作为研究对象,根据疾病类... 目的探讨血清微小核糖核酸-503(miR-503)和微小核糖核酸-520h(miR-520h)对妊娠期糖尿病(GDM)患者并发子痫前期(PE)的诊断价值。方法选取2019年12月至2021年12月于唐山中心医院产科定期产检并建档的GDM患者102例作为研究对象,根据疾病类型分为GDM+PE组(53例)、GDM组(49例)。另选取同期于唐山中心医院进行定期产检并分娩的57例健康孕妇作为正常妊娠组。比较3组糖脂代谢相关指标[甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)、空腹胰岛素(FINS)、空腹血糖(FBG)、餐后2 h血糖(2 h PG)]水平及血清miR-503、miR-520h表达水平、血清胱抑素C(CysC)、同型半胱氨酸(Hcy)水平;比较3组不良妊娠结局。采用多因素Logistic回归分析GDM患者并发PE的危险因素;绘制受试者工作特征(ROC)曲线分析miR-503、miR-520h单独及2项指标联合检测对GDM并发PE的诊断价值。结果3组孕周、年龄、孕前体质量指数、LDL-C水平比较,差异均无统计学意义(P>0.05)。GDM+PE组TC、TG、FFA水平均明显高于GDM组和正常妊娠组,HDL-C水平明显低于GDM组和正常妊娠组,差异均有统计学意义(P<0.05)。GDM组TC、FFA水平均明显高于正常妊娠组,差异均有统计学意义(P<0.05)。GDM+PE组和GDM组FINS、FBG、2 h PG、HbA1c水平均明显高于正常妊娠组,差异均有统计学意义(P<0.05)。GDM+PE组血清miR-503、miR-520h表达水平、CysC和Hcy水平均明显高于GDM组和正常妊娠组,差异均有统计学意义(P<0.05),GDM组血清miR-503、miR-520h表达水平及CysC和Hcy水平均明显高于正常妊娠组,差异均有统计学意义(P<0.05)。GDM+PE组不良妊娠结局总发生率为62.26%(33/53),GDM组为40.82%(20/49),正常妊娠组为10.53%(6/57),GDM+PE组不良妊娠结局总发生率明显高于GDM组和正常妊娠组,差异均有统计学意义(χ^(2)=4.692、32.125,P<0.05),GDM组不良妊娠结局总发生率明显高于正常妊娠组,差异有统计学意义(χ^(2)=13.059,P<0.05)。3组孕妇不良妊娠结局中产后出血、早产或过期产、胎盘早剥、新生儿窒息、宫内生长受限的发生率比较,差异均有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,CysC水平升高、Hcy水平升高、miR-503表达水平升高和miR-520h表达水平升高均为GDM并发PE的危险因素(P<0.05)。ROC曲线分析结果显示,血清miR-503、miR-520h单独及2项指标联合检测诊断GDM并发PE的曲线下面积(AUC)分别为0.755、0.847、0.935,2项指标联合检测的AUC大于miR-503、miR-520h单独检测(Z_(2项联合-miR-503)=4.210、Z_(2项联合-miR-520h)=2.708,P<0.001、0.007)。结论GDM并发PE患者血清miR-503、miR-520h表达水平升高,与妊娠不良结局呈正相关,二者联合检测对诊断GDM并发PE具有重要意义。 展开更多
关键词 微小核糖核酸-503 微小核糖核酸-520h 妊娠期糖尿病 子痫前期 空腹血糖
下载PDF
基于阈值图像分割结合深度学习的血细胞识别算法研究
20
作者 蔡润秋 巫琦 +1 位作者 马靖武 张译 《中国医学装备》 2024年第7期39-42,53,共5页
目的:探讨传统图像处理的阈值图像分割与深度学习相结合的血细胞识别算法,用于血细胞涂片的自动识别和分类。方法:使用全局阈值分割从血细胞涂片中提取血细胞并单独保存,对分割后的细胞图像进行人工标记和分类,以降低后续处理的硬件要... 目的:探讨传统图像处理的阈值图像分割与深度学习相结合的血细胞识别算法,用于血细胞涂片的自动识别和分类。方法:使用全局阈值分割从血细胞涂片中提取血细胞并单独保存,对分割后的细胞图像进行人工标记和分类,以降低后续处理的硬件要求。标记后的图像深度学习训练基于GoogLeNet预训练模型,生成可用于血细胞涂片图像自动识别的深度学习模型。使用已训练模型对测试集进行评价,并生成混淆矩阵和受试者工作特征(ROC)曲线下面积(AUC)值。结果:这种预处理被证明可以提高深度学习模型的训练以及后续使用模型识别的速度10倍以上。使用在线血细胞涂片图像数据集Raabin-WBC Data,模型训练的准确率达到93.06%,均取得了良好的结果。结论:基于阈值图像分割与深度学习相结合的血细胞识别算法,可极大提高血细胞识别分类的效率,保证血液相关疾病诊断的准确度。 展开更多
关键词 血细胞识别 阈值分割 深度学习 预训练模型
下载PDF
上一页 1 2 35 下一页 到第
使用帮助 返回顶部